1. Field of the Invention
The present invention relates to an encapsulating layer-covered optical semiconductor element, a producing method thereof, and an optical semiconductor device, to be specific, to a method for producing an encapsulating layer-covered optical semiconductor element, an encapsulating layer-covered optical semiconductor element obtained by the method, and an optical semiconductor device including the encapsulating layer-covered optical semiconductor element.
2. Description of Related Art
It has been known that, conventionally, an optical semiconductor device including a light emitting diode device (hereinafter, abbreviated as an LED device) is produced as follows: first, a plurality of optical semiconductor elements (including light emitting diode elements (hereinafter, abbreviated as LEDs)) are mounted on a substrate; next, an encapsulating layer is provided so as to cover a plurality of the optical semiconductor elements; and thereafter, the encapsulating layer is cut corresponding to each of the optical semiconductor elements to be singulated into individual optical semiconductor elements.
Among all, when the optical semiconductor element is an LED and the optical semiconductor device is an LED device, unevenness in emission wavelength and luminous efficiency is generated between a plurality of the LEDs, so that in such an LED device mounted with the LED, there is a disadvantage that unevenness in light emission is generated between a plurality of the LEDs.
In order to solve such a disadvantage, it has been considered that, for example, a plurality of LEDs are covered with a phosphor layer to fabricate a plurality of phosphor layer-covered LEDs and thereafter, the phosphor layer-covered LED is selected in accordance with the emission wavelength and the luminous efficiency to be then mounted on a substrate.
Also, an LED obtained by the following method has been proposed (ref: for example, Japanese Unexamined Patent Publication No. 2012-39013). In the method, first, for example, an LED is disposed on a pressure-sensitive adhesive sheet; next, a ceramic ink in which a phosphor is dispersed and mixed is applied thereto to be heated, so that the ceramic is temporarily cured; thereafter, the ceramic is subjected to dicing corresponding to the LED; and then, the obtained ceramic is fully cured to be vitrified so as to produce the LED. The LED in Japanese Unexamined Patent Publication No. 2012-39013 is to be then mounted on a substrate, so that an LED device is obtained.